im not sure but doesnt SQL server only installs if the requiered servicepacks are installed? mibby one of the SP is missing? just a guess but thats mostly why my installer stops after re-installing windows (without updating)

I am not passing any parameters..
The setup runs automatically as I have specified SQL SERVER 2005 EXPRESS as pre-requisite while creating setup-deploymeny project of my vb.net application.

So when i click my setup.exe it first runs setup to install sql server express as a pre-requisite.
I have added sqlserv.exe which i have downoaded form micorsoft site...this setup i have browsed and added to my APPLCIATION folder along with primary output while creating my setup-deployment project..

So when i run setup in client machine it gives error as i said earlier... one more I would like to say is
when i run the file sqlserv.exe manually then... all goes well in client machine.... it is installled successfully...
in short
if i run the file "sqlserv.exe" directly i.e. manually ..it is installed successfully... but when i run "setup.exe" which installs it as pre-requisite .it gives above error.. error "system cannot find file specified... as i said in previous post
any ideas?

Yes... the account is admin account ..
I would like to ask your one more thing...!

When we specify sql server express as a pre-requisite while setup and deployment project....
the list which opens.. is
"SQL SERVER 2005 EXPRESS EDITION SP2 X86" and we have to select that checkbox and immediate below is option to specify location of .exe of it..... options like download form vendor, download from application project location n ...specific location...
we select second option ... and we browse "SQLEXPR.exe" and add it as files in our setup project....

So i guess the ... the setupfile which i have downloaded "sqlexpr.exe" is not matching with ""SQL SERVER 2005 EXPRESS EDITION SP2 X86" .........

I don't know why you would *require* SQL Server be installed as a pre-req anyway. What if they already have an SQL Server on their network that they use for hosting production applications? In that case you wouldn't want SQL on the client machines and they should connect to the corporate server. But its up to you.

That being said I have never tried to make SQL a pre-req so I have no idea why its' failing.